BACKGROUND: To evaluate the clinical outcomes of valve-in-valve transcatheter aortic valve replacement (ViV TAVR) with newer-generation self-expanding Evolut valves according to the size of the failed surgical bioprosthesis. METHODS: This single-center retrospective study evaluated consecutive patients undergoing ViV TAVR with the Evolut Pro/Pro+/Fx between 2018 and 2022. These patients were compared based on the true internal diameter (ID) of the failed bioprosthesis, specifically ≤19 mm (small group) vs. >
19 mm (large group). The primary endpoint was a composite of all-cause mortality, stroke, myocardial infarction, and bioprosthetic valve failure. A Cox regression hazard model adjusted for covariates using propensity scores was used to assess the effect of the true ID on clinical outcomes. RESULTS: A total of 91 patients (small group, n = 35
large group, n = 56) were identified, and the median age of the entire cohort was 78 years. Patients in the small group were more likely to be female and have a small body surface area. The incidence of post-procedural mean gradient ≥20 mm Hg (40% vs. 8.9%, P = .001) and moderate/severe prosthesis-patient mismatch (63% vs. 38%, P <
.001) was significantly higher in the small group. During a median follow-up period of 25 (range: 1.0-66) months, all-cause mortality showed no significant difference between the groups (adjusted P = .104)
however, the rate of the primary composite outcome was significantly higher in the small group (adjusted hazard ratio 3.72, 95% CI 1.48
9.37). CONCLUSION: Valve-in-valve transcatheter aortic valve replacement for small bioprostheses was associated with worse early and midterm outcomes compared with those for large bioprostheses.